Lubricating-oil purifying and reclaiming system



3- Sheets-Sheet 1 F; R. C. BOYD Filed Sept. 26. 1924 EUJQOU EH13 LUBRICATING OIL PURIFYING AND RECLAIMING SYSTEM March 29', 1927.

Frederic 0v W nt/#04? March 29 1927.

. 1,622,278 F. R. c. BOYD LUBRICATING OIL PURIFYING AND RECLAIMING SYSTEM Filed Sept. 26. 1924 s sheets-Shana March F. R. C. BOYD LUBRICATING OIL PURIFYING AND RECLAIMING SYSTEM Filed Sept. 26. 1924 3 Sheets-Sheet 5 Patented Mar. 29, 1927.

.UNITED STATES v 1,622,278. PATENT OFFICE.

FREDERIC B. C, BOYD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE DE LAVAL SEPABATOB COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

LUBRICATING-OIL'PURIFYING AND BECLAIMING SYSTEM.

Application filed September as, 1924. Serial no. 740,001.

The-purification and reclaiming of lubricating'oilby means of centrifugal purifiers is well known, examples of comp'ete operative purifying and reclaiming systems embodying such. method of purification being set forth in the Kennedy Patent No. 1,318,086, dated October 7 1919, and i in the Boyd & Hapgood Patent No. 1,363,833, dated December 28, 1920.. In the'Boyd'& 10 Hapgood patent-isspecifically disclosed such a system applied to turbinedriven electric generators. In the Kennedy patent is specifically disclosed such a system applied to a marine engine. The Kennedy patent also discloses a cooler through which the oil from a drain tank is conveyed on its way to a gravity settling tank interposed between the drain tank and the centrifugal purifier. In any system of endless circulation of lubricatmg oil through engine bearings, cooling of the oil before returning it to the engine is always advisable and usually necessary. i

In the centrifugal purification of used oil i it is Well known that if the oil be heated, the

separation of water 'from the oilis facilitated, and therefore thepra'ctice of centrifuging the oil at a temperature as high as, or higher than, the temperature at which it enters the engine bearings, is well established. I have, discovered, however, that many impurities which cannot'be centrifugally removed from oil that is at a relatively high temperature can be removed it the temperature of the oil is substantially reduced. These impurities are soluble or miscible in the oil at a high temperature but not at a lower temperature. Consequently,

f present methods of purification do not efiect 40 the removal of these impurities, which may be, for convenience, designated hereinafter by the popular, it not wholly accurate, name of soluble sludge; On the otherhand, the

cooling of the oil to the .tem erature requiredto precipitate all the so uble sludge would make dehydration difiicult or impossible. Moreover, the volume of oil continuously flowing from and to the engine bearings is so great that it would be impracticafl /ble and uneconomical to attempt to cool it 7 through the extensive temperature range required to thtow the. soluble sludge out of solution. Either an impracticably long time would be required, orthe cooler would have to be of an impracticably large size. Morehydration and for the removal of dirt and over, it is undesirable to run the oil to the engine bearings at the temperature to which such oil would have ,tohe cooled to precipitate soluble sludge.

In order that the ditliculties above outlined may be better appreciated, it may be said that the oil flows from the engine bearings at a temperature of from 140 to 190 F., that the desirable temperature for deother insoluble impurities is not far from the temperature at which the oil leaves the engine bearings; that the temperature desired for the oil flowing to the bearings is about 100 to 130 F., and that the temperature required to precipitate soluble sludge is below 80 or 90 F.; 60 or F. being preferable.

According to my invention, in' order to purify the oilatthe difl'erent temperatures required to effectively remove water and other insoluble impurities on the one hand, and soluble sludge on the other liand, andto introduce the oil to the engine bearings at the desired temperature, and to avoid the employment of coolers of excessive capacity, I proceed as follows: The oil drained from the bearings flows into a reservoir. from which the oil is continuously pumped back to the bearings; This endless system of lubrication is comparatively old in the art of engine lubrication.

In the pipe connections from the reservoir to the engine bearings is interposed a main cooler adapted to reduce the temperature of the oi; (say) about 40 F, An independent endless flow of oil is established from the reservoir back to the retervoir, and in this circuit is. interposed a centrifuge adapted to dehydrate the oil and to remove from it all the contained impurities that are insolu bletherein at a high temperature From the pipe connections between the main cooler and the engine bearings Iarrange a bypass adapted to divert a portion of the oil (pref erably a very small proportion) to a second cooler (which I call a'super-cool'er) wherein the-temperature. of the oil is reduced to below (preferably 60 to'-80 F.),, WlllClll throws the soluble sludge out of solution; the

oil then passing to a centrifuge wherein I this recipitated matter is removed and from many in which my invention may be emthat only minor proportions V a modified supercooler.

Fig. 4 is a diagram of a modified complete V escaping from the several bearings passes bodied. Certain practical modifications will be mentioned hereinafter; and others'will suggest themselves, ormay be.v worked out, by thoseskilled in the art.

From the foregoing description it 'will understood that the bulk iof the oil flows direct from the reservoir to the engine bearingswithout being subjected to any treatment other than-a reduction in temperature through a comparativelysmallrange, and of the oil are diverted to the two purifiers. Bearing in mind, however, that t 1e contamination arising from a. single passage of oil through the engine bearings is very slight and that only after the oil has passedthroughthe bearings a great number of times is there any serious contamination, it will be understood that the constant, or even intermittent, diversion of only a'small proportion of oil throu h the purifiers will be effective to maintain the oil in a substantially pure condition.

In order that the system above described may be understood with more certainty, I have illustrated preferred apparatus in the accompanying drawings, in which-" Fig.1 is a diagram of a colnple'tesystem. Fi 2 is a longitudinal sectionthrough one Form of supercooler.

Fig 3. is a side view system.

Referrin first to Fig. 1: a represents a steam turbine and b an electric" generator directly connected therewith. The base of the engine isadapted to act as a lubricat ing oil reservoirc. From this reservoira pump 03 forces oil, through a pipe e, a main cooler f, a pipe g, and a distributing pipe 72.; connections therefrom to the several bearings being shown at i, j and la. The oil down pipes m, n and c te the oil reservoir c'. The described means for storing and cooling oil and conveying it from and'to the bearings is typical, but it should be understood that other arrangements are. known; and any 'arrangement in use in any given plant may be left undisturbed.

From the reservoir. extends a discharge,

pipe p, so located, preferably, that ittakes out oil from the lowest level of the'reservolr, where the oil most contaminated with water ordirt or 'both. The pipe p is of goose-neck sha of the oil in t e reservoir, into a funnel r, communicating with a valve pi e s, leading to a centrifugal purifier. t. T e purifier t removes the water, dirt and other'insoluble impurities from the oil, which is treated at the temperature of the oil in the reservoir, say 140170 F. which temperature is best adapted to effect complete dehydration.

m-ixture of partly cut away of ply, In exceptional cases,

e and discharges, at the level From the pipe g exte'nds a valved by-pass pipe w to a supercooler :0, wherein the oil is reduced to a relatively low temperature, say, to 80' F- In this cooler the soluble sludge is thrownout of solution, and the ail and precipitatedsludge flows through a valved pipe 10, to a centrifugalpurifienll. "VIII this centrifuge the oil is separated'from gits impurities. Such impurities may comprise a small percentage of insoluble matter, but theremoval of this material is incidental, the purpose of the centrifuge being to'separate the sludge which was dissolved in the oil before it was cooled and thrown out offsolution in the supercooler w., From the centrifuge 11, the purified oil passes through pipe 12 back tothe reservoirs, or, less'preferably, by means of 120 to ipe w and thence to the engine bearings. 11 pipe 12 may be interposed a filter 13. Either the centrifuge 11 or-the filter 13 may be eliminated, and dependence placed solelyon the centrifuge orthe filter to effect precipitation; or in some cases gravity may \sludge which is precipitated therein andiso Indeed it'isusually imact as a purifier, possible to avoid more or lessclogging of the supercooler by. precipitated sludge; and the supercdoler is so designed as to allow it to be readily cleaned.- I

. The supercooler a isshown in detail on Fig. 2. It comprises a long box or cylinder provided with together by tubes 21. The headers communicate respectivel with the oil'inflow pipe w and the oil out ow pipe 10. The'outer wall of-each header co'mprlses a hinged cover 22. 23 is a cold' water inlet and 24 a cold water outlet. By making the supercooler of suflicient length and restricting the rate of the flow'of the oil theret-hrough, the oil can usu ally be cooled to a Water at the temperature at which it comes from the city main or other source of supa slight artifical cooling of the water ma be desirable. More or less of the soluble s tated in the tubes 21 remains de osited therein. Atintervals, the flow of oi through the supercooler may be arrested and the end covers 22 may beswung open, and the tubes 21 :easily cleaned out,"witho'u't It is possible, b making the supercooler a: of considerable length, and by'providing for a' sufiiciently sluggish flowof oil thereback to the reserdismantling.

apump 121, may beforced through a pipe end headers 20, 20' connected i In sufiicient degree by udge that is precipias (above stated, dispensing with the necessity of providing any supplemental purifying means. It will be understood, therefore, that in'claiming the supercooling and purification of'this by-passed' oil, I mean to in- I cooler and clude asi'ipercooling which also effects sub stantial purification, as well as a supercooling followed by a special subsequent purifi-' cation by centrifugal force, filtration or gravity, or any combination of such purifying steps. The use of a centrifuge, however, is distinctly preferred, as it is highly desirable to effect an lassured elimination of all the soluble sludge, which is the most potent agent in degeneration 'of the oil. I

It has been found that the precipitation of soluble sludge in lubricating oil can often be facilitated if the oil is brought into direct and intimate contact with cold water. place of the supercooler w, I may employ a supercooler in which provision is madefor such direct and intimate contact between the oil and its cooling agent. Various forms of such a supercooler may be designed by the skilled engineer-- One practicable form is shown in'Fig. 3, in which 3 represents an elongated and preferably expanding tube connecting at one end with the oil inflow pipe w, and at the other end with the oil outflow pipe 10. Extending into the inlet end of the tube is a pipe having a discharge nozzle out of which cold water under pressure is forced in the form of a fine spray, which is disseminated throughout the oil. The liquid which emerges from the sludge precipitatory and which passes to the centrifuge 11 is a mixture of soil, water and precipitated sludge. Theadditioni of water to the oil is an'aid, rather than a hindrance,-to the centrifugal separation of the sludge; the water acting to agglomerate the sludge and as a vehicle to facilitate the outflow of sludge from the cen trifuge. 1

In a large installation, the use of two centrifiiges is not a serious cost factor; but in a small installation, it may befound desirable to avoid the use of more than one centrifuge. Where but one centrifugeis present, the oil in pipe 8 and the'oil in pipe 10 may be conveyed to the same separator.

Preferably, while oil is flowing to thecentri fuge through one pipe, its flow through the other isstopped.' Bearingin mind that Fig. 1 is a diagram, and not aworking device, thepipes s and 10 may be assumedto be fairly: 010 one to another or in place of e relatively hot oil to be dehydrated out of the bottom of the'reser-voir 0, through the pipe 1), 'trifuge t, a part of the oil entering the distributing pipe It may be by-passed through a valved pipe 40 to a'settling tank 41. The

funnel 1', pipe sand cenoutflow from tank 41 passes through pipe 42 to pipe" 12. Water, dirt and the like, with some oil, settle to the bottom of the tank;

flowing to the centrifuge from the settling tank 41, and vice versa. Itmay be possible,

however, to, allow both cold oil from the supercooler a: and heated 'oil from the settling tank 41 to enter the centrifuge together, as the. time during which the oil from the supercooler is exposed to contact with the heated oil from the settling tank is not suflicient to effect much, if any, redissolution of the sludge in the oil.

It is not essential that the oilthat has been thi ough'the main cooler 7 shall be conveyed direct to the engine bearings. It-may be much less. preferably conveyed back to the reservoir c and-the circuit of oil from the bearings to the reservoir and thence back to the bearings may be an independent circuit. Nor is it necessary, although it is highly desirable, that the oil that goes to the supercooler m shallhave passed through the main coolerf. Such oil may go to the supercooler without first going through the main cooler,

reservoir 0. 1

From the reservoir an oil outflow pipe 50 (in which is'interposed a pump 51) connects with a main' cooler 52, from which a pipe 53 extends back to the reservoir 0. Oil may I be by-passed either from pipe 50 through pipe 54, or from pipe 53 through pipe 55, to the supercooler 57 Preferably, the oil is by-passedjhrough pipe 54, and preferably, a s

o, a centrifugal purifier 56 is interposed in the pipe 54, so as to dehydrate the oil, at a desirably high temperature, before it is supercooled.- From the supercooler'the oil flows successively through a purifier 58 and a filter 59, although either may be omitted; and is then by means of pump 60, returned, through pipe '.61, to the reservoir 0.

In those claims which specify reclaiming oil from the bearings of 'an-engine, I do not mean to exclude equivalent uses. For example, in the case of a direct driven enerator, the oil to be purified would inc ude the oil from the generatorbearings; and in the case of a gear -driven generator, the oil to be purified would include the oil from 1 the gears,

Having now fully described my invention, what I claim and desire to protect by Letters Patent is:

1. The process of purifying and reclaiming oil from the bearings of an engine which consists inestablishing a flow of oil drained from the engine and differentiall cooling different fractional parts of sai oil. and purifying that part of the oil that has been cooled to the lower temperature. 2. Theprocess of purifying and. reclaiming oil from the bearings of an engine which consists in establishing a circulation of oildrained from the engine in two streams, cooling allthe oil so circulated but ceoling the oil in one stream to a tem erature'substantially below that to which t e remainder of the oil is cooled, and purifying the oil which has been reduced to the lower temperature. I 3

.3. The process of purifying and reclaimin' oil from the bearin s of an en ine which 5 m g i consists in drainin culation of oil fromsai .ing the oil so circulated, diverting a por-v consists in conveying oil drained fronf-the engine bearing to a body of oil, establishing from said body of oil, cooling H such flowing oil, diverting from the stream of cooled oil a minor portion thereof, and

cooling said diverted oil to a still lower temperature and purifying it.

4. The process of purifying and' reclaiming oil from'the bearings of an en' i'le which oil from t e engine bearing, to a body 0 oil, establishing a flow of oil from said'body of oil, splitting such flowing oil into two branches, cooling all such flowing oil but "cooling the oil in one branch. to a temperature substantially below that to which the remainder of the oil is cooled, and purifying the oil which has been cooled to the lower tem' ature, and con veying the two streams'of di l', one cooled and the other cooled and purified respectively to the engine and to said body of oil.

' 5. The process of purifying and reclaiming oil from the bearings of an en 'ne which consists in draining oil from t e engine bearing toa body of oil establishing a cirbody of .oil, cooltion of the cooled oil from the main stream, cooling the diverted cooled oil trra tempera-- ture substantially below that to which the main stream of.oil is cooled, and purifying the diverted oil, and conveying the'main stream and diverted stream of. oil respectively to the enginejbearing and to said body of oil. v

6. The'process of purifying and reclaim- .ing oil from the bearings of an engine which" consists, in draining ,oil from the engine bearing to a body ofoil, establishing a main' circuit of oil from said body of oil to the enginer'bearing, moderately cooling the oil in said circuitto the temperature at which it is desired to convey the oil to the engine out of solution bearing, and branching from said main circuit a minor circuit of smallrvolume and supercooling it to throw out of solution impurities that are soluble ata higher temperature and separating such impurities from the oil.

7. The process of purifying and reclaimingoil from the bearmgs f an engine which comprises establishing a flowof oildrained fromthe engine and cooling such oil to a temperature sufficiently below. 90 F., to throw out of' solution soluble sludge and separating such sludge from the oil.

8. The process of purifying and reclaiming oil from the bearings of an engine which consists in subjecting oil drained from the engine to two purifying operations, one of which comprises cooling the voil to a teming 01]. from the bearings of an enginewhich oil of relatively he contaminating ingredients thereof I comprises establishing a flow of oil' drained .fromthe engine-in two circuits, centrifugally purifying the oil in one of the circuits to remove therefrom I the insoluble contaminating ingredients thereof, and coolin oil in the other circuit to a temperature sufficiently below 90 F. to throw out of solution soluble sludge "and separating such sludge from the oil. 7 v 10. The process of purifying and reclaim ing oil from the bearings of an engine which comprises establishing a flow of oil. drained from the engine. in two circuits, centrifugally purifying the oil in. one of the circuits to remove therefrom the insoluble contaminating ingredients thereof, cooling all the oil in the other circuit but supercoolmg part of the oil in such othercii'cuit to a temperature.

substantially below that to which the rema'inder of the oil in that circuitis cooled v and to the 'temperature required -to throw the soluble sludge and separating the soluble sludge .from the supercooled oil.

circuit to the temperaturemt which it is desired to convey the oil to the engine bearin "s, andestabhsliing two other circuits of 11. The process of purifying and reclaiming oil from the bearings l of an engine which om the engine bearestablishing a main Of oil to the I Y oi in one-of which the oil is cooled to astill lower tem erature and purified and in the other of-w ich the oil is centrifugally purified at a relatively-high temperature.

12. The process of purifying and reclaim- I desired to conveythe oil to the engine bearings, and diverting a relatively small voluine of the cooled oil and cooling it to a still lower temperature and purifying it and returning it to the body of oil, and establishing an independent circuit of relatively hot oil from and back to said bodyof oil and centrifugally purifying the oil in the last named circuit. I

13. In an oil purifying and reclaiming system, the combination with an engine and an oil reservoir, of a cooler, a supercooler and pui'ifien n eans to circulate from the reservoir a relatively large volume of'oil through the cooler to the engine, and means to circulate a relatively small volume of oil through the supercooler and purifier.

14. In a lubricating oil purifying and reclaiming apparatus, the combination withian engine; a container forming an oil reservoir; oil conveying means comprising a cooler, an inlet pipe to said cooler from said reservoir and an outlet pipe from said cooler to the engine; of a branch pipe communicating with said oil conveying means and a supercooler and purifier communicating with said branch pipe.

15. In a lubricating oil purifying and ,reclaiming system, the combination with an engine and an oil reservoir, of two pipes, one of Which is adapted to discharge oil Into said reservoir, and the other of which is adapted to carry oil back to the engine, means 'to convey oil from said reservoir into said two pipes, means to cool the oil adapted to" so discharge through one pipe and means to super-cool and purify the oil adapted to r be so discharged through the other pipe.

16. In a lubricating oil purification and reclamation system, the combination with an engine and oil reservoir, and means to convey oil from said reservoir to the engine and to return drained oil to.the reseiwoir, of two purifying means, one adapted to treat the oil' at a relatively high temperature to remove insoluble impurities, and the otheradapted to treat the oil at a relatively low temperature to remove impurities in solution at the higher temperature, the second purifymg means comprising a supercooler.

17. In a lubricating oil purifying and reclaiming system, the combination with an engine and an oilreservoir, of two pipes adapted to discharge oil into said reservoir,

to circulateuncooled oil from the reservoir through the centrifugal purifier, and means to circulate a relatively large volume of oil from the reservoir through the cooler to the engine, and'a relatively small volume of oil through the supercooler and purifier,

19. In an oil purifying and reclaiming system, the combination with an engine and an oil reservoir, of a centrifugal purifier, an endless circuit from the reservoir through said centrifugal purifier back to the reservoir, a 'cooler, a supercooler and purifier, a pipe connecting the reservoir and the cooler, a pipe connecting the cooler with the engine, a pipe connecting the last named pipe wit-h the supercooler and purifier, and a pipe connection from the supercooler and purifier back to the reservoir. v

20. The process of purifying and reclaiming oil from the bearings of an enginewhich consists in establishing a flow of oil drained from the engine and subjecting a large fractional part of said oil to cooling and mixing a smallerfractional part of the oil with water to agglomerate the sludge and subjecting such'smaller fractional part to centrifugal force.

21. The process of purifying and reclaiming oil from the bearings of an engine which comprises establishing an endless circulaing oil from the bearings of an engine which COIDPIISBS the following steps: cooling to a temperature suitable for conveyance to the engine bearmgs; removing at a higher temperature impurities that areinsoluble atthat temperature; and cooling and purifying at a temperature below that at which the oil is conveyed to'the engine bearings. i

In testimony of which invention, I have 'hereunto set my hand, at Philadelphia, Penna, on this 15th day of September, 1924! FBEDERIC R. o. BOYD. 

